The purpose of this study was to examine the mechanisms by which anxiety malleability beliefs may predict social anxiety with a focus on the role of emotion regulation strategies. Specifically, we hypothesized that the relationship between anxiety malleability beliefs and social anxiety would be mediated by both the frequency and self-efficacy of cognitive appraisal or emotion suppression. Participants were 276 undergraduate students(124 males and 152 females) who completed a series of self-report questionnaires assessing anxiety malleability beliefs, the frequency and self-efficacy of cognitive appraisal and emotion suppression, social anxiety, emotion malleability beliefs, and depression. The results indicated that the relationship between anxiety malleability beliefs and social anxiety was mediated by different aspects of emotion regulation strategies. Interestingly, the self-efficacy of cognitive appraisal and the frequency of emotion suppression individually significantly mediated the effect of anxiety malleability beliefs on social anxiety. Specifically, low levels of anxiety malleability beliefs predicted lower levels of self-efficacy of cognitive appraisal and more frequent use of emotion suppression, which in turn led to higher levels of social anxiety. Based on these results, the theoretical and clinical implications as well as the limitations of the study were discussed.